1. Field of the Invention
The present invention relates to liquid ejection heads and methods for producing liquid ejection heads.
2. Description of the Related Art
A typical example of a liquid ejection head for ejecting a liquid is an inkjet recording head applied to an inkjet recording system for ejecting ink onto a recording medium to perform recording. An inkjet recording head usually includes ink channels, ejection energy generators provided in parts of the channels, and fine ink orifices for ejecting ink by the energy generated by the ejection-energy generators.
To improve adhesion between a substrate having energy-generating devices and a member forming walls of liquid channels, Japanese Patent Laid-Open No. 11-348290 discloses a technique in which the substrate and the member forming walls of channels are bonded with an intermediate layer, formed of polyetheramide, disposed therebetween.
Japanese Patent Laid-Open No. 2009-274266, on the other hand, discloses a method in which a blank pattern of characters corresponding to information about the history of an inkjet recording head is formed in an intermediate layer disposed between a substrate having energy generators and walls of liquid channels so as to follow the walls of the channels.
Recently, the pattern of channels has become increasingly finer, and an intermediate layer having a finer corresponding pattern needs to be formed. The intermediate layer can be formed such that end surfaces thereof are substantially perpendicular, or close to being perpendicular, to the surface of the substrate in view of, for example, constraints on the positional relationship between the intermediate layer and the member forming the channel walls and the contact area between the intermediate layer and the member forming the channel walls.
However, if a blank pattern is formed in the intermediate layer to display information about the inkjet recording head, as disclosed in Japanese Patent Laid-Open No. 2009-274266, it may be difficult to visually recognize the contours of the information display pattern, and it may therefore be difficult to identify the pattern, depending on the transparency of the layer overlying the intermediate layer.